Is COVID vaccine safe for patients with cardiovascular disease? In a major study, researchers said that COVID-19 vaccination is not associated with an increased risk of heart attack or stroke in patients with established cardiovascular disease.
The study was published in Cardiovascular Research, la journal of the European Society of Cardiology (ESC). On the study, author Dr. Esther W. Chan claimed that their study showed that pre-existing cardiovascular disease should not prevent people from getting vaccinated against COVID-19. Chan is from the Li Ka Shing Faculty of Medicine, The University of Hong Kong.
“Vaccination is particularly important for this group since cardiovascular disease is associated with worse outcomes and a higher risk of death after COVID-19 infection,” the author said..
The researchers claimed that this was the first study to examine the association between COVID-19 vaccines and the risk of major adverse cardiovascular events (MACE) in patients with cardiovascular disease. The study focused on BNT162b2 and Corona Vac, the only COVID-19 vaccines authorised for emergency use in Hong Kong.
METHOD
The researchers used data from electronic health records managed by the Hong Kong Hospital Authority. This covers around 80 per cent of hospital admissions, and vaccination records provided by the Hong Kong Department of Health. The first two doses of vaccine were included in the analyses. Individuals were not permitted to switch between vaccine types for the first two doses.
The researchers used self-controlled case series study design, which was developed to assess the risk of adverse events after vaccination. Each patient was compared with himself/herself for the risk of MACE up to 27 days after each vaccine dose (exposure period) versus the non-exposure baseline period.
Dr. Chan said: “A traditional cohort study would compare the vaccinated group with the unvaccinated group but the two groups could have different baseline characteristics. A self-controlled case series avoids the issue of differences between groups since each individual acts as his/her own control.”
A total of 2,29,235 patients with cardiovascular disease were identified, of which 1,764 were vaccinated and experienced MACE during the study period (662 received BNT162b2 and 1,102 received CoronaVac). The researchers stressed that there was no evidence of an elevated risk of MACE after the first or second dose of BNT16262 or CoronaVac.
